Field of the Invention
The invention relates to an antenna and, more particularly to a multiband antenna.
Description of the Related Art
As communication technology develops, electronic devices and wireless applications of the electronic devices are widely used. For example, a 3G smartphone and a personal digital assistant (PAD) are frequently used in daily life. Moreover, wireless communication of the electronic devices is powerful by cooperating with various kinds of antennas, which makes user feel more convenient.
Since mobile communication devices become smaller and thinner gradually, the volume of the antenna becomes smaller. However, in order to maintain a good quality of communication, the bandwidth requirement of the antenna become wider, and the radiation pattern and the radiation efficiency of the antenna should also be taken in consideration. Thus, designing an antenna to meet all the requirements becomes more challenging.